A method for aerobic treatment of drilling wastewater

Abstract

The invention belongs to the field of treatment of industrial water. An aerobic treatment method for drilling wastewater comprises the following steps: (a) acclimatizing aerobic degrading bacteria; (b) feeding the bacteria at the first time: feeding 0.1 to 0.5 percent of the aerobic degrading bacteria, 20 percent of aerobic activated sludge and 20 to 30 percent of biological stuffing into aerobic treatment equipment according to the volume of the aerobic treatment equipment; (c) performing biofilm culturing treatment: feeding air into the aerobic treatment equipment, feeding supernate of diluted drilling wastewater into the aerobic treatment equipment every day, and controlling the CODcr value of the wastewater in the aerobic treatment equipment at 500 to 1,000 mg / L until biological zooglea appears; (d) supplementing the aerobic degrading bacteria; (e) performing settling; introducing water discharged from the aerobic treatment equipment into an aerobic settling pool for settling. According to the aerobic treatment method, the degrading effect of the drilling wastewater can be enhanced.

Description

technical field [0001] The invention belongs to the field of industrial water treatment. Background technique [0002] In oil and gas exploration, drilling and production operations, in order to ensure the normal operation of drilling operations and provide high-quality wellbores and stable well walls for later operations, a large number of high-color, high-pollution, and refractory polymers are used in drilling operations. mud system. However, a large amount of drilling fluid enters the drilling wastewater during use, causing the drilling wastewater to become industrial wastewater with high solid content, high chroma, high organic content, high heavy metal content, and high mineral oil content. This industrial wastewater has high concentration, Pollution, difficult to degrade characteristics. [0003] The hazards caused by the discharge of such industrial wastewater into the environment include: ①Wastewater flushed into rivers or infiltrated into formations will cause COD...

AI Technical Summary

Problems solved by technology

[0005] The disadvantages of the above-mentioned aerobic reaction treatment method are: ① Relying on the aerobic microorganisms in the aerobic sludge, the effect may be obvious at the beginning of operation, but during the sewage treatment process, due to the high toxicity of the pollutants contained in the drilling wastewater , will cause a large number of aerobic microorganisms to die. If the death rate of microorganisms is greater than their growth rate, and there is no supplementary sewage from the outside to degrade microorganisms into the aerobic reactor, then the entire aerobic treatment system will eventually be paralyzed; ② because of this treatment method There is only aerobic activated sludge in the reactor, so the load resistance is poor. Fluctuations such as increased drilling wastewater flow, water quality changes, and environmental changes will cause the loss of aerobic activated sludge, and the aerobic microorganisms will also be lost along with the sludge. Or die, resulting in the treated wastewater failing to meet the discharge standards, or failing to meet the treatment requirements of the next wastewater treatment process, such as high CODcr, high levels of pollutants in wastewater, etc.

③ The aerobic microorganisms attached to the aerobic sludge are used for treatment, and the aerobic microorganisms in the aerobic sludge are not separated and purified, so many factors are affected (such as the number of aerobic microorganisms in the aerobic sludge, type and degradability, etc.), it is prone to large fluctuations during operation